The present invention relates to a crown closure, particularly, to an easy opening crown cap for sealing bottles, which, departing totally from the conventional hand-open types where the pull-to-open or tearing off technical art is followed, employs a novel pull-it-over technical concept.
The crown cap of the present invention includes a cap body having substantially a flat top, a crimped portion formed on the periphery of the cap body and an outwardly extending finger tab integrally joined to a part of the crimped portion.
Crown caps, being the most simple and economic in construction, are employed for sealing liquid containers like wine bottles, sauce bottles or aerated water bottles. In general, a crown cap is made of a tinned plate in a cap shape, and relying totally on the twenty-one included teeth in the crimped portion, closely embraces the protruding ring at the mouth of the bottle due to the flexibility and elasticity of the metal and tightly seals the mouth of the bottle to provide air-tightness or liquid-tightness due to the gasket or disc inside its flat top. Although the crown cap is simple in construction and has a wonderful function, on opening the bottle, a tool, such as an opener, is required for pulling the included teeth apart from the protruding ring at the mouth of the bottle in order to separate the cap from the bottle mouth.
There has since been much research in regard to how a crown cap can be easily opened out without having to rely on a tool. Among the prior art in the field are, for example, U.S. Pat. Nos. 3,382,997 to Tsuji and 3,937,349 to the present applicant, which disclose different designs of crown closure with easy open means for bottles. However, since most of these crown caps are formed by stamping of tinned plate, which is of relatively hard material, to split open the caps with a finger tab or pull ring has not been that simple, particularly because the purpose of opening the bottle can not be accomplished if the pulling force applied is insufficient. When the finger tab is lifted forcefully because of difficulty in the pulling, the various projections and the cut portions on the crown cap itself and on the finger tab are all likely to cause cuts to fingers and uneasiness to the user. Furthermore, when the finger tab which has broken the crimped portion off is further pulled upward, the remainder crimped portion, that is, the remainder portion of the included teeth, is still hooked to the protruding ring at the mouth of the bottle and will thus require further application of force for pulling upward in order to separate the cap from the bottle mouth. Particularly, the said included teeth of the crimped portion that have been torn apart are of considerable sharpness, which, either during the opening of bottle or upon being discarded away, are likely to cause cuts to people. Still further, when the crown cap which has been torn open is to re-seal the mouth of the bottle, it requires that the parts which have been pulled open or the other deformed parts be made to return to their original condition in order to achieve the result of re-sealing of the bottle temporarily.